McHenry County Department of Health - Environmental Health

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Ticks and Lyme Disease

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Ticks and Tick-Borne Disease

More than 15 species of ticks are found in Illinois, but the three most prominent are the Black-legged Tick, or Deer Tick, the American Dog Tick, or Wood Tick, and the Lone Star Tick. In general these ticks are most active from March through November.

Ticks are not insects; they belong to the arachnid family (i.e. scorpions, spiders, mites). Ticks do not jump or fly, instead they climb or drop. They wait in tall grass or weeds for a suitable host to pass by. When brushed by a moving animal or person, they let go of the plant and climb onto the host.

Ticks are very skilled disease carriers because they attach firmly, feed very slowly and often go unnoticed. Their sensory organs can track small amounts of gases, such as carbon dioxide left by warm blooded animals and man. It is impossible to tell by sight which ticks are infected with disease, so it is important to avoid tick bites when in areas where ticks may be present.

The risk of tick exposure is greatest in wooded areas, but ticks can also be carried by animals into houses by pets.

Common Ticks of Illinois

The most common tick in Illinois is the American Dog Tick, also known as the Wood Tick. Unfed males and females are reddish brown and about 3/16" long. After feeding, the female will become about 1/2" long (about the size of a small grape), and have a large silver colored spot behind the head. Males have silver lines on their back and do not get much larger after feeding.

Although uncommon in Illinois, the American Dog Tick can transmit Rocky Mountain Spotted Fever, Tularemia, and possibly Ehrlichiosis to humans.

AMERICAN DOG TICK

The Lone Star Tick is found primarily in the southern half of Illinois. The larva is very small, about the size of the period at the end of this sentence. The nymph is about pin head sized. Adult Lone Star Ticks are about 1/8" long and brown. The adult female has a white spot on the middle of its back. They are often mistaken for the Black-legged or Deer Tick because they are so similar in size. The Lone Star Tick is most active from April through the end of July.

The Lone Star Tick can transmit Rocky Mountain Spotted Fever, Tularemia, and possibly Ehrlichiosis to humans.

LONE STAR TICK

The Black-legged Tick, commonly known as the Deer Tick, can be found in wooded areas along trails. The larvae and nymphs are active in the spring and early summer. Adults may be active in both spring and fall.

The Black-legged Tick is a three host tick (feeds on three different hosts during its two year life cycle). If a larva or nymph feeds on an animal infected with Lyme Disease, it can become infected and can pass the bacteria to other animals and humans during subsequent feedings.

The Deer Tick is established along the river corridors of Illinois and can be found in most Illinois counties. Illinois residents are more likely to encounter Deer Ticks while traveling to Wisconsin, Minnesota and the northeastern states.

DEER TICK

The Brown Dog Tick, also known as the Kennel Tick, is found throughout the U.S. This tick feeds on dogs and rarely bites people. The adult is reddish-brown and about 1/8" long and usually attaches around the ears or between the toes of a dog to feed. This tick does not survive Illinois winters outdoors. The Brown Dog Tick is not an important carrier of human disease.

NOTE: Pictures are magnified to highlight their markings and should not be used for size comparison.

Lyme Disease

Lyme Disease is a bacterial disease transmitted by the bite of an infected tick. The Black-legged or Deer Tick is a known carrier of Lyme Disease in the northeast and north central United States. Not all ticks carry disease, and a bite of a tick does not always result in the development of Lyme Disease. Ticks generally need to be attached for 36 to 48 hours before they can transmit Lyme Disease.

Deer Tick engorging
Photo of a Deer Tick or
Black Legged Tick as it engorges

Symptoms

Symptoms of Lyme Disease vary greatly from person to person. The diagnosis may be delayed because in the early stages, the symptoms are so similar to the flu and mononucleosis, and many people do not realize that a bite even occurred.

Early Stages of Lyme Disease

Lyme Disease usually appears 3 to 30 days after exposure to an infected tick. The symptoms may include:

Fatigue
Chills and fever
Headache
Muscle and joint pain
Swollen lymph nodes
Skin rash (often with a "bull's eye" appearance)

The "bull's eye" rash occurs in about 60% of the cases and may appear 3 days to 32 days after the bite. The rash is typically warm to the touch, but not painful.

Bull's Eye Rash

Late Stages of Lyme Disease

The following symptoms may not appear until weeks, months or years after a tick bite:

Arthritis (usually occurs in large joints, especially the knees)
Facial paralysis
Neurological and cardiac problems
General malaise
Fatigue

If you experience these symptoms, and have had a possible exposure to ticks, contact your physician.

Two-Year Life Cycle of a Tick

Tick life cycle

Ticks have a two-year life cycle that begins in early spring when adult female ticks lay their eggs on the ground. The eggs hatch as the temperatures rise. The larva feed on mice and other small animals from summer until early fall. These larvae may become infected with Lyme Disease while feeding. Once infected, the tick will remain infected for the rest of its life allowing it to transmit the disease during subsequent feedings.

After the first feeding, the larvae becomes inactive and rests through winter in leaf litter, under rocks or woodpiles or any place where they can find sufficient cover. During this time, the larva molts into a nymph.

The next spring, the nymphs emerge. These nymphs are responsible for the majority of Lyme Disease cases in humans In the fall, they molt into adults. The adult positions itself on the tips of grass or shrubs and climbs onto deer and other large mammals as they pass by. Once the adult tick has selected a host, it feeds and mates. Once mated, the female tick drops off, lays her eggs, and the cycle begins again.

Protecting Yourself from Ticks

The best way to protect yourself against tick-born disease is to avoid tick bites. Taking the following precautions will reduce your chances of tick bites.

Walk in the center of trails so weeds do not brush against you.
Apply insect repellent containing DEET (20 to 30%). Always supervise children in the use of repellents. Follow label instructions.
Always wash hands after using any insect repellent.
Wear light colored clothing so that ticks are more visible.
Wear long sleeved shirts and long pants.
Tuck long pants into your socks and boots.
For added protection, wear a head covering or hat.
Check yourself and children every 2 to 3 hours for ticks.
Examine pets for ticks.
Be sure to wash skin treated with insect repellent when returning indoors.
After being outdoors, remove clothing and wash and dry at a high temperature.
If you have an unexplained illness with fever, contact a physician. Be sure to tell your physician of a possible tick exposure.

Tick life states

Tick Removal

Remove a tick from your skin as soon as you notice it. It usually takes at least 36 hours for an infected tick to transmit Lyme Disease.

Tick Removal Tool

Do not use bare hands to remove the tick because the tick secretions may carry disease.
If using a tick removal tool, place the thumb and finger against the skin near the tick's location and stretch the skin taut.
Slide the tick removal tool under the tick.
Slowly lift the tool until the skin puckers and the tick releases.
If using tweezers, grasp the tick firmly with the tweezers as close to the skin as possible and gently, but firmly, pull it straight out.
Be careful not to squeeze, crush or puncture the body of the tick, which may contain infectious fluids.
If a tick removal tool or tweezers are not available, grasp the tick with a piece of tissue or cloth.
Occasionally, the head of the tick will become detached and remain under the skin. The tick can no longer transmit disease at this point and will fester its way out of the skin.
Wash the area with soap and water and use a disinfectant on the bite site.
Clean the tick removal tool or tweezers with an alcohol wipe.
Place the tick in a plastic bag for possible identification and testing. The tick may be identified at the McHenry County Department of Health or the University of Illinois Extension Office in Woodstock, Illinois.
In some cases, ticks may be sent to a laboratory for testing of Lyme Disease.
If you experience an unexplained illness with fever, contact your physician. Be sure to inform him/her that you had possible exposure to ticks.

Folk remedies that have been used in the past to remove ticks can be dangerous and even increase your chances of contracting a tick transmitted disease.

Do not use petroleum jelly, a hot match, nail polish or other products to remove a tick. Other techniques including using a soap-soaked cotton ball and swabbing it for a few seconds should not be used. By manipulating the tick, you can cause the tick to regurgitate and/or increase its salivation - both which can increase the risk of infection.

Tick Identification and/or Testing Services

Frequently Asked Questions

Q: What is Lyme Disease?
A: Lyme Disease is the most common tick-borne infection in North America and is transmitted through the bite of an infected tick.

Q: If I am bitten by a tick, does that mean that I will develop a tick-borne illness?
A: No, not all ticks carry disease. It is impossible to tell by sight which ticks are infected, so it is important to avoid tick bites whenever possible.

Q: Do all ticks transmit Lyme Disease?
A: No. Not all ticks carry the bacterium and a tick bite does not always result in the development of Lyme Disease.

Q: Which tick-borne disease is most common in Illinois?
A: Lyme Disease is the most common tick-borne disease in Illinois. Keep in mind that the bite of a deer tick can occur while traveling to Wisconsin, Minnesota and other surrounding states.

Q: Which tick transmits Lyme Disease?
A: In Illinois, the tick which transmits Lyme Disease is the Black-legged or Deer Tick.

Q: How common is the Black-legged or Deer tick in Illinois?
A: The deer tick is well established in some areas in Illinois, especially along the forested river corridors. That is not to say that you will not encounter ticks anywhere in the State.

Q: How do ticks acquire Lyme Disease?
A: Deer ticks acquire the bacterium that causes Lyme Disease by feeding on small mammals infected with the bacteria. The Deer Tick has a two year life cycle, and can acquire the disease at any feeding during that two year cycle.

Q: What are the symptoms of Lyme Disease?
A: Symptoms vary greatly from person to person. A ring-like or bulls eye rash occurs in about 70 - 80% of the cases. This rash is often accompanied by fatigue, chills, fever, headache, swollen lymph nodes and joint and muscle pain.

Q: When should I seek medical attention?
A: If you experience a rash or any unexplained illness accompanied by fever and have had possible tick exposure, consult with your physician. Explain that you may have been bitten by a tick.

Q: Can Lyme Disease be treated?
A: Yes. The usual course of treatment for Lyme Disease is antibiotics. The type and use varies depending on the patient’s symptoms and whether he/she was treated early in the infection.

Q: What is the prognosis of Lyme Disease?
A: Patients treated with antibiotics in the early stages of the infection usually recover rapidly and completely. Most patients, who are treated in the later stages of the disease, respond well to antibiotics. Varying degrees of permanent damage to joints or the nervous system can develop in patients with late Lyme Disease. Lyme Disease is rarely life threatening.

Q: How can I avoid getting bit by a tick?
A: The best way to avoid tick bites is to avoid tick infested areas. If you are in wooded areas with tall grass and weeds, follow these precautions:

Wear light colored clothing, so you can spot a tick on your clothing.
Wear long sleeved shirts and long pants. Tuck pant cuffs into socks.
Apply insect repellent containing DEET (up to 30%) to clothing and sparingly to skin. Always wash hands after using any insect repellent and follow label directions.
Walk in the center of trails so weeds do not brush up against you.
Check yourself and your children every two to three hours for ticks.

Q: How long does it take for a tick to transmit Lyme Disease?
A: In general, a tick needs to be attached for 36 hours before they can transmit the Lyme disease bacterium.

Q: Can I only get Lyme Disease if I have been in the woods or tall grassy areas?
A: NO. Ticks can also be carried by animals into lawns and gardens and into houses by pets.

Q: Which diseases can be transmitted by the bite of an infected tick?
A: The most common diseases transmitted by ticks are Rocky Mountain Spotted Fever, Ehrlichiosis, Lyme Disease and Tularemia.

Q: What is Rocky Spotted Fever?
A: Rocky Mountain Spotted Fever is an infectious disease transmitted to humans by the bite of an infected tick. Symptoms of Rocky Mountain Spotted Fever are a sudden onset of a fever (which can last for two to three weeks), severe headache, fatigue, deep muscle pain, chills and rash. The rash typically begins on the legs or arms.

Q: In Illinois, which tick carries the disease for Rocky Mountain Spotted Fever?
A: The most common carrier is the American Dog Tick. The adult tick is dark brown or black, with white markings behind the head. The Lone Star Tick has been known on occasion to carry the disease.

Q: What is Ehrlichiosis?
A: Ehrlichiosis is a disease of humans and animals caused by bacteria that are transmitted through a bite of an infected tick. The Lone Star Tick, the American Dog Tick and the Deer Tick have been associated with this disease.

Q: What are the symptoms of Ehrlichiosis?
A: Symptoms vary, but the most common include fever, headache and muscle aches. A person may experience loss a appetite, nausea and vomiting, occasionally accompanied by a rash.

Q: What is Tularemia?
A: Tularemia is a bacterial disease associated with animals and humans. Not known to spread from person to person, people may become infected with Tularemia through:

Bite of an infected tick, deerfly or other insect
Handling infected bodies of dead animals
Eating or drinking contaminated food or water
Breathing in the bacteria

Q: What are the symptoms of Tularemia?
A: The symptoms from Tularemia may include, fever, chills, muscle pain and lack of energy. Antibiotics are used to treat Tularemia.

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